re PR rtl-optimization/5079 (Reference to static const int not eliminated during optimization)

PR optimization/5079
	* call.c (build_conditional_expr): Use decl_constant_value to
	simplify the arguments.

	PR optimization/5079
	* g++.dg/opt/static3.C: New test.

From-SVN: r70881

gcc/cp/ChangeLog

@@ -1,3 +1,9 @@
+2003-08-28  Mark Mitchell  <mark@codesourcery.com>
+
+	PR optimization/5079
+	* call.c (build_conditional_expr): Use decl_constant_value to
+	simplify the arguments.
+
 2003-08-26  Dan Nicolaescu  <dann@ics.uci.edu>
 
 	* parser.c (struct cp_token): Use enum bitfields.

gcc/cp/call.c

@@ -3358,6 +3358,8 @@ build_conditional_expr (tree arg1, tree arg2, tree arg3)
     }
 
  valid_operands:
+  arg2 = decl_constant_value (arg2);
+  arg3 = decl_constant_value (arg3);
   result = fold (build (COND_EXPR, result_type, arg1, arg2, arg3));
   /* We can't use result_type below, as fold might have returned a
      throw_expr.  */

gcc/testsuite/ChangeLog

@@ -1,3 +1,8 @@
+2003-08-28  Mark Mitchell  <mark@codesourcery.com>
+
+	PR optimization/5079
+	* g++.dg/opt/static3.C: New test.
+
 2003-08-27  Zdenek Dvorak  <rakdver@atrey.karlin.mff.cuni.cz>
 
 	* gcc.misc-tests/gcov-10b.c: New test.

gcc/testsuite/g++.dg/opt/static3.C

@@ -0,0 +1,35 @@
+// { dg-do link }
+
+class Foo {
+public:
+  // No out-of-class definition is provided for these class members.
+  // That's technically a violation of the standard, but no diagnostic
+  // is required, and, as a QOI issue, we should optimize away all
+  // references.
+  static const int erf = 0;
+  static const int foo = 1;
+};
+
+int one()
+{
+  return Foo::foo;
+}
+
+int two()
+{
+  return Foo::foo + Foo::erf;
+}
+
+int three(int x)
+{
+  return x ? Foo::erf : Foo::foo;
+}
+
+int i;
+
+int main ()
+{
+  one ();
+  two ();
+  three (i);
+}